Pump



L. W. LEWIS PUMP 3 Sheets-Sheet 1 Filed April 26, 1948 3 M 0 Z 7 2 4 & w 5 k 7 7 J /f; 1. "fi 4 3 4 w wflm lnnentor (Ittomeg June 30, 1953 w, LEWIS 2,643,816

PUMP

Filed April 26, 1948 3 Sheets-Sheet 2 [ca/Is W ZeW/s 3nnentor June 30, 1953 L. w. LEWIS 2,643,815

PUMP 7 Filed April 26, 1948 3 Sheets-Sheet 3 Lou/'5 W dew/s ZSnnentor Patented June 30, 1953 UNITED STATES ATENT OFFICE This invention is concerned with a pump, and particularly with a pump which is adapted to deliver either small or large quantities of fluid without appreciably changing the pressure, vol

ume or temperature of the fluid being delivered.

Most pumps heretofore used, such as reciprocating pumps, centrifugal pumps, rotary pumps, gear pumps and air pressure pumps, do change the pressure, the volume or the temperature of the fluid being delivered by the pump.

In order to deliver a constant flow of fluid, reciprocating pumps heretofore used must build up a head, or store a quantity of liquid or fluid under pressure, so that when the fluid is delivered, as through a small aperture, the fluid will flow continuously. Most such pumps have a reserve chamber, sometimes cushioned with air so that more liquid will be admitted into the reserve chamber by compressin the resilient air or other fluid in it, thus getting a continuous flow of fluid.

Gear pumps, reciprocating pumps, rotary pumps, centrifugal pumps and air or gas pressure 4 pumps heretofore used have delivered a constant flow of fluid because of the pressure exerted against it. 7

Most pumps used in the past have been unable to deliver very small quantities of fluid in exact and fixedly measured quantities or increments, because most of these pumps depend for their efliciency upon the speed of operation and the pressure used for forcing the fluid to the delivery point. Therefore, the fluid delivered by these pumps is necessarily changed in volume, p res-v This is especially true in change in the pressure, volume and temperature of the fluid delivered; I

Inaddition to the objects above set out, this invention has among its objects the following:

and in which each quantity so moved will remain constant in volume, pressure and temperature.

(1)) To provide .a' pump with a fluid piston operated by gravity.

(c) To provide a pump with fluid operated valves, which valves are operated. by gravity.

((1) To provide method and apparatus for pumping fluids which will pump various, meas- (a) To providea method and apparatus for moving fluids in successively moved quantities;

ured quantities of fluid without appreciable change in pressure, volume or temperature of th fluid while being pumped. (e) To provide method and apparatus for moving fluid in which there is delivered a continuous flow of fluid, or a series of spaced quantities of fluid, without appreciabl change of volume, pressure or temperature of the fluid moved.

(f) To provide a pump which may be adapted for the circulation of a fluid in measured quantities Without appreciable change in the volume or temperature of the circulated fluid.

(g) To provide a pump which may operate as a vacuum pump for exerting a steady and gentle suction.

(h) To provide apump which will deliver a plurality of fluids simultaneously without appreciable change in pressure, volume or temperature of such fluids.

(i) To provide a pump which will exert steady and gentle pressure.

a closed conduit system so operated as to prevent contact of the moving fluid with the atmosphere and/or contamination therefrom. v

' (is) To provide an oscillating valve which is opened and closed by the gravitation therein of a body of liquid. 1

(Z) .To provide method and apparatus for moving successively entrapped quantities of fluid within a fully enclosed pumping system operated at the environmental pressure, and in which the force of gravity is employed to valve and to move the successively entrapped quantities of fluid.

(m) To provide fluid measuring and moving method and apparatus employing liquid-actuated valves, and means for tilting, cocking, inclining or leaning such valves so as to cause the liquid therein to be moved by gravity to open and close the valves, and in which there is further employed a liquid piston for drawingfluid into a receptacle associated with each of such valves, and also for displacing such fluid in such receptacles, depend- Fig. II is an enlarged, partially sectionalized.

side elevational view of a typical cylinder and valve assembly shown in Fig. I, with the mountings therefor. I

of the cylinder and valve assembly shown in Fig. I with the mountings therefor.

Fig. IV is a perspective view of a modified form of cylinder and valve assembly which may be used with my pump.

Fig. V is a schematic representation showing various positions in which valve assemblies, shown in Fig. I, may be found during one complete cycle of the pump.

Fig. VI is a perspective view of the five way collector tube used in 'my device, showing the connector tubes and discharge hose connected thereto.

Fig. VII is a partially sectionalized elevation of a liquid container with siphon tube therein which may be used in conjunction withmy pump for pumping liquids.

Fig. VIII is a perspective view 'ofa pair'of'mcd-i- 45 are fixed to the upper ends of the shafts 26, 29, 30 and 3|, respectively, between lower brackets 46, 41, 48 and 49, and upper brackets 46a, 41a, 43a and 49a, respectively. These brackets are held firmly in place to the shafts by means of set screw collars 53 and 5! and set screws 50a and 51a, as is clearly illustrated in Figs. II and III.

Mounted on the upper ends of cylinders 42, 43, 44 and 45, and made integral therewith (if desired), are valve assemblies 52, 53, 54 and 55, respectively. These valve assemblies commun'icate with the respective cylinders to which they are connected. As shown in Fig. I all of the valve assemblies and their associated cylinders are exactly alike, and the shape and the construction thereof may be understood more fully by refied valve and cylinder assemblies employed to adapt the pump for delivering a multiple flow of fluids simultaneously.

Fig. IX is a schematic representation showing the various positions of two cooperatingvalve assemblies on my pump, during one complete cycle of operation.

In thedrawings numeral references are used to. designate various parts of my invention; and the numeral I designates the base of the framework. of the pump. I The four upright frame members 2, 3, 4' and 5, together with. the. cross braces 21 and 21a, complete the supporting frame-work of the pump.

An electric motor 86 has a gear '61, attached tor-the rotor thereof, which articulates with gear 6, which in turn drives the gears i, 8 and 9 in the directions shown by arrows .cn the respective. gears. It is to be noted that the gearsS, 1, 8 and, .9 are all. of. the same diameter and are in the same ratio so that they all turn .at the same rate of speed. The gears E and 8 are journaled to and supported by the cross. braces .2! and 21a by means of rods 6a and M .respectively, which rods. arerotatively carried by the cross braces 21 and. Zla through the use of bearings, such as 6?), Scand 8b.

The gears l and 9 are mounted on. the axles I0 and l I, respectively.- which axles pass through, and are carried. by, bearings 1.2 and 13. The opposite ends of the axles I0 and H pass through theupright members 3 and. 2, respectively, to be secured to the crank arms I4 and H, respectively, by means of bolts 1 Maud Ha, respectively. The crank arms. and i6 maybe attached to the ends of the axles. H3. and H respectively, in. the same manner that crank arms .14 and I! are at tached thereto. The shafts 28, 29,30 and 3l are securedtc the outer ends or the crank arms 14., I15, 16. and H, respectively, by means ofv bearing members-22; 23, 24 and 25, which bearing mem b'ers are respectively held in place by pivot bolts 1%;19, and2l.

The. shafts 28,. 29, 3B and 3| are supported by, and slide through, oil-lite bushings, such as those shown at 32- and33. These bushings are rigidly connected to the ends of axles 34 and 35, which axles pass through and are supported by the bearings 36, '37, 33 and 39, so thatthe axles are rotatively connected between the upright frame members 2, 3, 4 and 5.

The opposite-ends of the axles 34 and 35 are free to rotate independently, and even in opposite directions, since each of these axles is made of two separate members held together by differentialsleeve couplings 4'0 and 4| The glass or plastic cylinders 42, 43, 44 and upstanding hollow branches 5'! and 57a; the,

valve assembly 54 has upstanding hollow branches 58 and 58a; and the valve assembly 55 has upstanding hollow branches 59 and 59a.

.The branches on the respective valve assemblies may be made integral with, and communicate with their associated cylinders, through hollow connecting stems, as illustrated by the numerals 60 and 6!.

Each of the valve assemblies 52, 53, 54 and 55 is provided with .a quantity of mercury 62, 63, Hand 65, placed in the lower horizontal part thereof. This mercury is in suflicient quantity to block the passage in the lower arm of the valve assembly when thevalve assembly is tilted from the horizontal, as shown in Fig. I, butnot sufficient in amount to prevent the free communication between the upper branch of the valve and the piston through the connecting stem.

The lower end of each of the cylinders 42, 43, 44 and 45 is extended, as clearly illustrated in Figs. Iland III, to form a tubular projection, designated as 42a, on the bottom thereof.

A rubber, or other flexible tube 68, is attached at its opposite ends to the extension on the bottomof cylinders 42 and 45, so that these cylinders communicate with each other through the tube '68.

Likewise, the cylinders 43 and 44 are connected by the flexible hose 69 in the same manner that cylinders 42 and 45are connected.

The tube 68 has aquantity of mercury 70 therein; which, as shown in Fig. I, extends up into cylinder 42, since the cylinder 45 is there shown at a higher level thancylinder 42. The level ofthe mercury is indicated by the dotted line to B.

Since by force of gravity the ends of the column of mercury in tube 68 will always seek the same level, the mercury will rise into the cylinder 42 or 45 when one is lower than the other. Cylinder 421s shown-in a lowered positioned in Fig. I; .and the mercury has risen into it.

Likewise, flexible tube 69 has a quantity of mercury H therein, the level of which is indicated by the dotted line to A. In Fig. I the mercury is shown as having risen in the cylinder 43, it being lower than cylinder 44.

The volumes of mercury Hi and H act as fluid pistons for the pump.

A five-way collecting tube i2 is connected to,

581and 59aof valves 52, 53, 54 and 55, respectively,

'byzmeans offlexible hoses 14,15, 16 and TI, re-' spectively. This is also shown in Fig. VI.

. The discharge hose I3 is connected to the outlet branch (3a,fortheypurpose of discharging fluid from the pump;

Fig.v IV shows a modified form of valve assembly designated as 18; which has, instead of a cylinder like that of 42, va cylinder I9, which is adapted for the delivery of very small quantities of fluid. In this form the upper part of the valve assembly is constructed the same way as the valve assemblies 52,53, 54 and 55.. It has upstanding hollow branches 80 and SI, and the branches 8!] andBi may be made integral with,-and they communicate with, the cylinder 'IQthrough extensiontube 82.

a The cylinder I9 is attached-to the rod 84 by means of the clamp member 83. The flexible tube 85 (which is the same in construction and operation as tubes 68 and-69, shown in Fig. I) is attached to the cylinder 19' and leads oifto another cylinder (not shown) which cooperates withthe valve assembly l8 in the same general manner that valve assemblies 52 and 55 cooperate.

However, the openings through the branches 8!] and 8|, connecting extension 82 and cylinder I9 are the same size; and there is, therefore, no change in the pressure, volume or temperature of the fluid pasing through it. The modified constructionshown in Fig. IV assumes great importance in work of exact, precise and scientific nature. 7

Fig, VIII shows-another modified form, wherein tWo valve assemblies are mounted together on the same rod, each such valve assembly being capable of delivering a different quantity and/or kind of fluid at the same time. valve assembly 95 is secured to the rod 94 by means. of bracket members 92 and 93, which brackets are above and below the. cylinder 9|. Thevalve assembly 96, with cylinder 98, is attached to the cylinder 9| by means of the clamp member 9 'I. Such an arrangement lends great flexibility to mypump and greatly enlargesits usefulness.

My pump may be employed in a multitude of technical and exact operations, in both laboratory and industrial work, moving single or plural streams of fluid, and/or simultaneously moving plural streams of unlike fluids, and mixing them in predetermined quantities, if andas desired. It will circulate and/ or mixstreams of gas and/or liquids in operations of aerating, impregnating, compounding, admixing, diluting, titrating, absorbing, heating, cooling, dissolving, coloring, and chemically uniting, ad infinitum.

To operate the pump, electric'motor E6 is energized,'causing the gears 6, I, 8 and 9 to rotate in the directions indicated by arrows thereon. The gears I and 9, being fixed to their respective axles l0 and II, will cause thecranks I4, l5, I6 and I! to rotate, carrying their respective shafts 28, 29, and 3| with them. It may be seen that the crank l4 turns in th opposite direction from crank l1; and crank I5 turns in the opposite direction from crank I6.,

As shown, the

, It should be noted that the outer ends of the cranks describe a circle; and that the outer end of crank I4 is degrees out of phase with the outer end of crank I5; that the outer end of crank I6 is 90 degrees .out of phase with the outer end of crank II; that the outer end of crank I4 is degrees out of phase with the outer end of the mercury seeks to maintain its level in the I 60 into the cylinder 42.

crank I1; and that the outer end of crank I5 is 180 degrees out of phase with the outer end of crank l6.

Therefore, when the outer end of crank I4 is atvalve assembly 55 will be in its highest position in its orbicular movement The same applies to valve assemblies 53 and 54.

Various indeed'may be the mechanical devices and contrivances which employ the essential principles of my invention. The method of this invention. may be employed without using the particular mechanism disclosed in the drawings. For instance, other contrivances may be used to tilt thevalves, and still further devices may be employed for alternately raising and lowering the separate valves of an associated pair of valves,

such as a see-saw contrivance, having valves on the opposite ends of the see-sawing member. Also, there may be employed a rocking structure,

roughly comparable to a childs rockinghorse,

providing valves on the upper ends of the separate rockers, or on the superstructure arranged above such rockers; and an unbalanced eccentric member may be used as a valve-tilting means.

My method may be practiced where there are two associated and related fluid-controlled and gravity-operated valves, each being provided with its own receptacle (moving in unison therewith). Any suitable contrivance which will alternately raise and lower these valves may be employed,'

and any means which effects a tilting'of the valves, first one way and then the other, will do. Then the only other thing needed is a liquid piston moving in a flexible conduit which communicates with each of the receptacles indicated, so as to alternately enter and recede from these receptacles, as they are successively raised and lowered (with respect to one another). That eX- plains my method in a nut-shell.

However, for the sake of clarity, let us now return to an exposition of the particular device made plain in the attached drawings, it being an'abundantly operable and one preferred form of mechanism for employing my method.

Since all of the valves, with their associated cylinders, pistons, shafts and cranks, operate the same way, the operation and function of the pump may be more easily and readily understood by describing the action of one of the valves and its associated cylinder and piston, during one complete cycle of operation.

Therefore, for purpose of illustration, we will trace and describe the action of valve assembly 52 and its associated cylinder 42, piston 68, red 28 and Crank [4.

Assuming that the pump shown in Fig. I is in operation, the outer endof crank I 4 is moving in a counterclockwise direction, and the cylintier-42 and the valve assembly 52 are moving upward. As the cylinder moves upward, the mercury I51 moves downward in the cylinder, since piston tube 88.

a The mercury, moving downward, will draw fluid in through the branch 56 and connecting stem As the valve assembly auras re:

the mercury 52 'flowsover to the left, and'closes the opening through the branch 56a, thus closing the outletcommuni-cationabetween the cylinder d-Zrand the collecti-ng'tube' It.

When the valve assembly '52 reaches the high.- est part of its a'rcuate movement, it starts downward and .is tiltedto the :right,-causing the mercury 52: to move over to the right and close the opening through :the branch 56.

As the valve "assembly 52 and the cylinder 42 move downward; the mercury, column II! will move upward, and into the cylinder 42, thus forcing the fluid in the cylinder out through branch 55a.-.(.-wh-ichris now open) and through the 001-. lecting tube It, into the five-way collecting tube l2-sa nd out through the discharge" hose I3.

'lhusthe :fluid drawn into the cylinder 42 on thetupwa-rd-movement of the valve assembly 52 'is discharged out of the cylinder on the downward movement of the valve assembly 52'.

When the outer end "of crank I4 reaches the lowest pointin'its circular rotation, it willbegin to move upward again, and the valve assembly 52 =will be again tilted to the-left, the mercury 62 will again how overto-close the outlet passage throughthe branch 55d, the mercury It will again begin'to reoedefrom cylhider '42 and fluid will again be drawninthrough the branch 56 and into the .cylinder.-42. Ihus, a complete cycle of operation has been completed.

Fromthewforegoing description it may be generally said that when eitherof the valve assemblies is moving upward, fluid will be drawn into itsassociated cylinder; and when the valve is moving downward, fluid is being discharged from the-cylinder.

Thecylinder Aland the cylinder 45 are connected together, and they communicate with each other, by means of flexible piston tube 58, which has a columnof mercury I therein.

.Now since the crank 14 is rotating in the opposite direction from crank III, and the outer ends of said cranks are 180 degrees outof phase, the valve 55 and cylinder are always moving downward when-the valve 52 and cylinder 42 are moving upward; and while valve '52 is taking in fluid through branch 55, the valve 55 is discharging fluid through branch 59a-into collecting tube 11., through. the five-way collector tube I5 and out through the discharge tube I3.

At the position in which we see valves 52 and 55 in Fig. '1, the valve 55 is on its downward movement and therefore discharging through thebranch 59a; and the valve 52 is on'its upward movement; and fluidis being drawn in through the branch "56. The mercurycolumn I0 is moving downward in the cylinder 42 and upward through the'tube 58 and into the cylinder 45, thus forcing the fluid which has collected in cylinder 45, while valve 55 was in its upward movement, out through the branch 59a.

The valves 53, 54 and 55 are exactly the same in construction and operation as has been related above in reference to valve 52, which is of suitable and typical construction.

The cylinders 53 and M, which operate in conjunction with the valves 53 and 54, respectively, are 'connectedtogether by the flexible piston hose 69,- in the same manner that valves 52 and 55 are connected together; and they function together in the same manner as was related above in reference to valves 52 and 55 (which latter valves are typical).

It should be noted that the outer ends of the cranks I5 and I6 are also 180 degrees outof phase and that they are rotating in oppositedirections; so thatwhen valve 53 is moving upward, and fluid is being .drawn in through the branch 5i and into the cylinder 43, the'valve 54 is moving downward, and fluid is being discharged through branch 58, in the same manner'that was related above in reference to valves 52 and 55.

Now since the outer ends of cranks :I I and I5 are degrees out of phase in their circular movement, and the outer ends of cranks I6 and I! are the pump at 90 degree spaced intervals during :one complete cycle of operation of the pump.

Thus, by regulating the speed of the pump a continuous flow of fluid may be obtained.

For the purpose of illustrating the direction of in-flow and out-flow of fluid through the valves,

': the valves 52 and 55 are shown in Fig. V separate and apart from the rest of the pump. In thisillustration the relative positions of the valves 52 and 55 are shown while one is discharging fluid,

and the other is taking in fluid. Valve 52 as shown in solid lines in this illustration is on its way up and fluid is being taken in through branch 55 and through connecting stem 60 (as indicated by arrows) and the valve 55 as shown by solid lines is on its way down and fluid is being discharged through branch 59a out of the cylinder.

45 (as is shown by arrows). The valve 52 as shown by dotted lines is on its way down in its arcuate movement, and fluid is being discharged through branch 56a (as shown by arrows); and

. valve 55 as shown by dotted lines is at the same time on its Way up and fluid is being taken in through branch 59 (as shown by arrows).

The arcuate movement of two cooperating valves such as 52 and 55, shown in Fig. I, and. the relative positions thereof during one complete. cycle of the pump, is shown diagrammatically in.

Fig. IX.

In this illustration the valves 99 and I00 are caried by the rods E02 and I03, respectively. The rods I02 and I03 are rotatively carried by the outer ends of the crank arms I04 and 'I05,.respectively. The cranks I04 and I 05 are secured. to, and rotate with, the axles Ma and I05a, respectively. The valves 99 and I50 are connected by a flexible piston tube IIII. The valve 99 has a quantity of mercury I I16 therein; and valve I00 has a quantity ofmercury It] therein.

When set in motion, the outer end of crank I54 describes the circle I08, in the direction indicatedby arrows; and the outer end. of crank I55 describes the circle I09, in the direction indicated by arrows.

and is taking in fluid at the place and direction Itis to be noted that the two. cranks are revolving in the opposite directions Thevalve 99, being carried on the upper end of .each complete cycle of the have a continuous flow.

'tion shown in Fig. IV.

indicated bythe arrow; and" the valve 100 is 'moving downward, and it is discharging fluid in valve 286 and discharged by the-valve 99, as indiv cated by arrows on the respective valves.

-When arm I84 has reached position 3, the valve 99 is still on its way down; and crank 185 has reached the position III, and the valve W9 is on its way up; and fluid is being taken into the valve |00,'and discharged from the valve 99, in the directions'indicated by arrows. When the crank I04 has reached the position 4, the valve 89 has been tilted to the left and has started up, and is taking in fluid in the direction indicated by the arrow; and arm I85 is in position IV, and valve I88 is on its way down, and is discharging fluid in the direction indicated by the arrow;

Thus, it will be observed that the valves 99" and me are always 180 degrees out of phase in their arcuate movement; and that while one is taking in fluid, the other is discharging it.

The foregoing diagrammatic illustration and description applies either to the cooperating valves 52 and 55 or to cooperating valves 53 and '54. It should be remembered, however, that the outer ends of arms I4 and I5 are 90 degrees out of phase in their arcuate movements; and that the outer ends of arms l6 and I! are 90 degrees out of phase in their arcuate movements, so that each of the valves '52, 53, 54. and 55 completely discharge alternately, at 90 degree intervals, on

pump; and thus we Should an intermittent discharge be desired, any one or more of thevalves could be disconnected from the five-way discharge tube 12, so

that only the valves left connected would discharge through thedischarge tube 13. The disconnected tube leading from the valve would be and discharge through the free ends of the branches 56, 51, 58a and 59. A steady suction may bemaintained by using all four valves, or an intermittent suction may be created by merely disconnecting one or more of the valves from the collecting tube 12, in the manner described above.

The amount of fluid pumped depends upon the volume of the cylinder or reservoir underneath the valve assembly, which cylinder or reservoir is indicated as at 42 in Figs. II and III.

,By increasing the volume of this reservoir-the volume of the pump may be increased; and by decreasing the volume of this cylinder the volume of the pump is decreased.

The pump may be made to accurately pump :very smallquantities of fluid by making the valve substantially in accordance with the modifica- In this modified valve, the valve'assembly is indicated as 18, which may beconstructed as a unitary tube with upstanding branches 80 and jecting tube 19. The tube 19 serves as the cylinder or reservoir in which fluid is stored and from which it is discharged. Sincethe interior volume of the modified tube 19 is very small,

the amount of fluid which is discharged by this valve is'very small. 'In a preferred form of this -modification, the internal diameters of members l8, I9, 88, 8| and 82 are made to be the same. Connected to the cylinder 79 is theconnector tube 85, which may be extended to connect to a duplicate of valve assembly 18 on the opposite side of the pump. The valve assembly 18 may be secured to the rod 84, which carries it"by means of the clamp member 83.

Since mercury is a contaminant for many liquids, it may be desired to use the assembly shown in Fig. VII in conjunction with my pump, when pumping liquid. This special assembly consists of a container 86, in which-there is a stopper 81, with two holes therethrough. Through one of these holes passes a tube 89, which is bent to form a syphon. Since both ends of the tube are exactly the same length, no fluid will be syphoned. Through the other hole of the stopper is passed a tube which extends into the fluid 98 in the bottle to exactly the same depth as the immersed end of the syphon tube 89, thus equalizing the hydrostatic pressure in the container. The discharge tube 13 of the pump is connected to the outer end of the tube 88. Air is pumped by the pump into the container 86 through the tube 88. The volume of air pumped into the container will displace a valve assembly like that shown in Figs. II and III mounted in conjunction with a valve assembly like that shown in Fig. IV; and both are mounted on the same rod 94. With this arrangement one quantity of fluid could be pumped'by the valve assembly 96. Of course each of the'separate valve assemblies would be connected to its own collector tubelike that shown at 12. This arrangement can be multiplied, and thus wouldbe particularly useful when it is desired to mix several different kinds and quantities of fluids at the same time, and in predetermined quantities or in related volumes. vBy using the adaptation shown in Fig. VII, a gas and a liquid couldbe mixed or several gases and liquids could be mixed at the same time. 1

The pump could be further modified to serve *the'function of a circulating pump. To do this it would only be necessary to connect thefree branches 56, 51-, 58a. and 59 on the valves 52, 53, 54'and 55 to an assembly exactly like that made up of connector tubes 74, 15, 16 and I1, five-way collector tube 12 and discharge tube 13. The discharge tubes of the two assemblies could be .each connected to the receptacle or container through which it is desired to circulate fluid; and we would in effect have a circulating pump.

y In order to measure the exact amounts of fluid pumped, a counter I 12 may be mounted on the base member I. .This counter has a trip arm H3 .which is tripped by the crank arm 15 on each revolution thereof, so that, by calibration, the exact amount of fiuidpumped can be determined by the number of revolutions indicated, on the counter.

The fluid can thus be pumped in counted and metered quantities.

The amount of fluid pumped can of course'be varied by varying the speed of operation of the pump, up to its maximum eificiency.

This pump is particularly useful in laboratories and in scientific work, where it is required to pump varied quantities of, fluids, and particularly inminute amounts, without change in the pressure, volume or temperature of the fluids; or where it is desired to pump spaced and metered quantities of fluidi-n which each quantity moved ,by'the pump will remain constant in volume, pres- ,sure. and temperature while travelling through the pump. It may, of course, have commercial application, wherever such results are desired.

For ins ance, it may be particularly useful. in

pumping highly volatile explosive or inflammable .fluids,, s uch as; gasoline or nitro-glycerin. The fluid pistonand valves cause no friction or pressure and, there is, therefore, no heat (created by operation of the pump.) which can come into contact; with fluid being pumped, Thus the danger Qt: fire or explosion whenpuinping explosive or inflammable fluids is greatly minimized.

My pump. may beemployed, in the, preparation of.- pharmaceuticals... medicaments, anesthetics and solu ions and mixtures which are required to beigerm free, chemically pure and sterile. The closed. systemof. moving fluids which I .employ preven s. contamination or bacterial presence .fromthe air. My. no-pressure system of pumpin allows the. movement and/or mixture of fluids without alteringtheir physical properties in any vice may be set to. deliver the required quantity of. anyfiuid, over a certain time. as, for. instance, a penicillin solution into. the vein of a patient, where itisdesired thatit be deposited in a certain concentration and at a certain spot, internrittently. or. continuously, for many hours, or even days, without ceasing. Or, it could be used to. continuously. evacuate the stomach of a .patient by. converting it into a vacuum- .pump, in .the manner hereinbefore described. The valve arrangement would prevent any. undue suctionthat might injure the stomach of the patient, and the suction may be regulated by decreasing or increasing the volume ofv mercury in. the valve.

Aeration of water or other liquids, may be: efiected by having pumped, therein washed and cleansed air, or oxygen, continuously and in given proportions, without surcease. Even air may be purifledand made sterile, or freed of pollens, dusts and allergy producing materials through the use of my invention.

, Saline solutions may be made in a given strength continuously, by the dilution of a concentrate thereof; and such a solution may be fed continuously (or intermittently) to open wounds, as a cleansing antiseptic. Thetechnical, scientific and laboratory uses of my invention are numberless; and'its industrial uses are many. 7

Although I have illustrated and described the preferredforms of my invention, it is to be understood that other and further changes and modifications may be made therein without departing from the spirit and scope of the appended claims.

I claim:

1. In-a. pump of the class described, a pair of gravity biased liquid operated valves, each of said valves having an inletand an outlet and a common conduit connecting the inlet and outlet; a cylinder extending below each of the valves; a tube connecting the upper portion of each cylinder with the upper side of the common conduit .in said flexible conduit; means for rotating. said cylinders out of phase and in a substantially-common plane and for tilting the valves back and forth.

2. In a pump of the class described, a pair of gravity biased liquid operated valves; an inlet for each said valve; an outlet for each said valve and a common conduit connecting the inlet and outlet of each valve; a cylinder extending 'below each of the valves; 2. tube connecting the upper portion of each cylinder with the upper side. of the common conduit of thevalve associated with such cylinder; a flexible conduit providing communication between the cylinders; a liquid piston movable within said flexible conduit; means for rotating said cylinders out of phase and in a substantially vertical common plane, and to impart tilting motion to said valves; a collecting vessel; a common outlet for said collecting vessel; a separate tube connected to the outlet of each said valve, said tubes being connected at their remaining ends to the collecting vessel, whereby fluid pumped through each valve may be discharged through the common outlet.

3. In a pump of the class described, a. pair of gravity biased liquid operated valves, each of said valves having an inlet and an outlet and a }common conduit connecting the inlet and outlet;

operating to tilt each of said valves, said tilting being so arranged and operated. as tic-reverse. the angle of tilt at the highest point and again at the lowest point of-thearcuate moyem'entof each iof said cylinders.

4. Ina combined valve and cylinder for use in :a pump of the class described, a pair of upstanding branches; a substantially horizontally disposed conduit connectingsaid-branches; a body ofliqui'd disposed in said conduit in sufficient quantity to close either of said upstanding branches when the valve is tilted in the directionof the branch to be so closed; a cylinder extending below the conduittand a tube extending .above. the conduitand connecting the upperpart of the conduit, and, the upper partvof the. cylinder, the. said cylinder, upstanding branches,

conduit and connecting tube being carried by common supports whereby they may be moved in unison.

5. In a pump, a pair of cylinders; a flexible conduit connecting such cylinders; a liquid piston so disposed in said conduit as to be movable therein by force of gravity toward whichever end thereof is lower; a separate liquid operated valve arranged to communicate with each cylinder, each such valve having a substantially horizontally disposed conduit with an upstanding branch at each end thereof, and suflicient liquid in the conduit to alternately flow by gravity to open and close the branches when the valve is alternately tilted in opposite directions; a tube connecting the upper part of the cylinder and the upper side of the conduit; whereby fluid is admitted to its associated cylinder when the said valve is tilted in one direction and the cylinder is raised, and fluid is discharged from the cylinder when the valve is tilted in the other direction and the cylinder is lowered; means for raising and lowering said cylinders alternately, and for alternately tilting each valve in different degrees of inclination.

6. In a pump of the class described, two pairs of gravity biased liquid operated valves; an inlet for each valve; an outlet for each valve; a common conduit connecting the inlet and outlet; a separate cylinder connected to and communicating with both inlet and outlet on each of said valves; said cylinder extending below the valve; a tube extending above the valve and connecting the upper end of the cylinder with the upper side of the common conduit of the valve; a flexible conduit connecting the cylinders on each pair of valves and causing communication therebetween; a separate liquid piston movable within each of said flexible conduits; means for so rotating each pair of valves and associated cylinders as to cause them to move out of phase and in a common plane, and for effecting reversible inclination in each of said valves.

'7. In a pump of the class described, two pairs of gravity biased liquid operated valves; an inlet for each such valve; an outlet for eachsuch valve; a common conduit connecting the inlet and outlet; a separate cylinder communicating with the inlet and outlet on each valve; a tube extending above the valve and connecting the upper end of the cylinder with the upper side of the common conduit of the valve; a separate flexible conduit connecting the cylinders of each i4 ated as to reverse the angle of tilt at the lowest point and again at the highest point in the arcuate movement of the cylinder communicating with such valve.

8. In a pump of the class described, two pairs of gravity biased liquid operated valves; an intake branch on each valve; an outlet branch on each valve; a horizontal conduit connecting the branches; a separate cylinder extending below and communicating with each such pair of branches; a connecting tube connected to the upper end of the cylinder and to the upper side of the conduit; separate flexible conduits connecting the cylinders of each pair of valves; 2. separate liquid piston movable within each flexible conduit; means for rotating each pair of valves, together with their associated cylinders, in vertical planes, each valve in each pair of valves being 180 degrees out of phase with the other valve in such pair in their arcuate movement, and the valve in one pair being 180 degrees out of phase with the diagonally disposed valve in the other pair in their arcuate movement, said rotating means also operating to impart a tilting motion to each of said valves at the lowest point and also at the highest point in the arcuate movement of each of said valves with associated cylinder; and a commoncollecting conduit so connected to one branch of each of said valves as to receive fluid discharged therefrom.

9. In a pump of the. class described, two pairs of gravity biased liquid operated valves, an inlet for each valve; an outlet for each valve; a compair of valves; a separate fluid piston movable mon channel connecting inlet and outlet; a separate cylinder extending below and being attached to each such valve and arranged to communicate with both inlet and outlet thereof through the common channel; a tube extendingabove the valve and being connected to the top of said cylinder and to upper side of the common channel; a flexible conduit connecting the cylinders of each pair of valves and providing communication therebetween; a liquid piston movable within each such flexible conduit; means for vertically rotating said cylinders together with their associated valves out of phase, said means also operating to impart tilting motion to each valve at the lowest point and again at the highest point in the arcuate movement of its associated cylinder; a collecting tube; a separate tube connected to the outlet of each valve, the said tubes being connected at their remaining ends to the collecting tube, whereby the fluid moved through the pump is delivered into the common discharge conduit; and a counter adapted to be actuated on each cycle of the pump whereby the volume of fluid being delivered may be measured.

LOUIS W. LEWIS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 386,717 Pontallie July 24, 1888 1,707,624 Brown Apr. 2, 1929 1,745,979 Calvert Feb. 4, 1930 

